Linked layers means all the properties are connected, change one design and you change them all. Not every property of the selected item is linked, so things such as the scale and rotation are not but the pixels, fill colors for shapes etc. Change one pixel in one and all the other designs will also change.
Select a layer and then go to the layer menu and use the duplicate linked command. You will then have a second or third etc and they will all be 'the same' as the first and any pixel (or any the properties that are included for that type) change will then be replicated, such as that applied by a filter effect etc
To see the properties associated with the design, go to the panel and you can link (or remove) that property and that varies from pixel / adjustment / live effect / text etc, so the text has different properties to that of a pixels There are a few overlaps such as fill and stroke as well as fx styles etc (so you can have your bevels and shadows connected or not simply by clicking the little icon of the far left of the entry (if you are using vectors then the properties in the panel list blending modes, opacity, fx styles, vector shape parameters, vector fill and vector stroke. Any of them can be disabled so a change to the stroke will not be reflected in the others. You can also click the same icon to re-connect. You can also use the arrow keys on the panel to move back and forth between all the related designs.
I would suggest setting up a shortcut via the preferences for the duplicate linked command and then you can create multiple entries quickly, not sure why that menu entry does not have a shortcut as it is one of the more useful features of the application. I would suggest avoiding the macro feature as the macros seem to introduce some issues and what seems to be a simple act becomes a little more complicated.
You can create some text such as the word 'max' and then repeat that throughout the image and using different sizes as well as different angles. You can then go to a single entry and change that such as change the text and all the text will change. You can change the font, the color, single characters, add styles etc
Adjustments can also be connected by the same approach. Simply create an adjustment via the layer menu and then duplicate that via the menu command. You can only join the same type of adjustment so there is no connecting black and white to the HSL etc. You can connect HSL to HSL and any change to one of the adjustments will change in the others and you can also change the blending mode etc. You can create all kinds of color combinations using this approach.
You can use the feature with patterns as well. Create a design and then convert it into a pixel design (it needs to be pixel for the pattern feature to work) and then go to the layer menu and create a pattern based on the selection. Re-size, rotate, shear etc the design. You can also use the command to create the 'same' pattern but you can continue to scale and rotate but those properties are not connected, the others are such as blending mode.
All kinds of filter effects can be applied to the pixels such as deform or twirl and any change to one l will be propagated to the other, so your deform effect will be added to all the others. If you are using a design as a shape, you need to convert this to a pixels / raster before you do any duplication otherwise you will find none of the effects etc are connected.
You can do the same with shapes created via the star tool, polygon tool, etc. In that case, the properties are connected so any item duplicated will be also connected so star 1 changes the number of points to 10 then the second connected star will also change the number of points to 10. You can uncouple the vector shape parameters via the panel and any changes then will not be reflected in the others.
It should be noted that it can be quite easy to break the relationship by making immensely complicated groupings etc and moving things around, you will find that at some point the connection between the properties is lost. You will also find in some situations that the duplication entry is disabled and you cannot use it but the more conventional duplication will still be available.