You can create Affinity Photo linked layers via the layer menu, they are a special type more like a symbol in most application where one thing changes, all the instances change in the same way such as the color information or the style etc. If you have a pixel design, duplicate using the second duplication option and you will see a little chain icon appear next to it in the panel. You can repeat this multiple times and create many entries and any change to the pixel content will then be updated even if it is 100+ designs.
It should be noted that this all works best with pixels. If you are using shapes or type then you will have to convert them to pixels by using the merge commands or rasterize, as long as it is a pixel layer you can work with it. If it is a shape, when it converts, you will lose the connection between all the entries and it will not work. Supposedly there is a way to re-connect them but I have never mastered it and it is one of those features that works for some objects but not others.
Liquify persona is a powerful feature where you can enter another set of commands and tools to manipulate a pixel layer and you can distort designs in countless ways by using the powerful set of brushes included (you can also access it via the live filter layers). There can always leave this and return to the normal set of commands within the application. It is the second item along on the control bar.
Inside this special area, you will see the toolbox and panels have changed though some have been carried forward from the standard area. You have a range of brushes down the left side and the default is push forward and it is a powerful warping feature and that can be manipulated via the brush panel. You can also manipulate the mesh via its panel and you can set the reconstruct to 0 through to 100% and modify any of the warps with 0% putting back to before you entered. There is also a twirl brush, pinch etc and they can be used to create many interesting distortions. There is also a clone tool which means any distortions in one part can be applied to another section in the mesh. You can then click apply and the distortions will be applied and you are returned to the regular space.
Weirdly, even though it is not a filter, you can use the filter menu and repeat command and you can re-apply it multiple times to further distort the artwork and all those changes will be reflected in all the entries.
You can also fade the effect, you can go to the layer menu and fade command and then reduce the result of the distortion (not the reconstruction though) and also change the blending mode from normal to difference or darken etc which depends on the underlying image if it has any effect. Again, all the connected entries will also be changed with the fade.