[Peter Hickson] “I have been able to link the two layers, but the expression changes the values of my linked layer rather than moving them relative to the master layer.”
comp("CompName").layer("LayerName").position will give you the position of the layer named ‘LayerName’ in the composition ‘CompName.’ However, I’m a little concerned that your question might be more complicated than that…
The position value returned will be the position of ‘LayerName’ inside of ‘CompName,’ so if you’re using one of these (or both) as pre-comps inside another composition and trying to get position values for the layer in the ‘CompName’ relative to the composition it’s appearing in then it gets a little more complicated:
thisComp.layer("CompName").toComp(comp("CompName").layer("LayerName").position);
…should do it!