There are more than one method, I was thinking you want Door Center to be placed/sized between the two door components. And Door Left may not be at origins (0,0). So I was thinking you need Door Left location + it’s size, and from Door Right’s location, you minus Door Left’s position plus it’s size to give you the distance between.
So for Door Center I put:
X:Door Left side!X+Door Left side!LenX
LenX:=Door!LenX-Door Left side!LenX-Door right side!LenX
But now that I rebooked, I noticed you have a small moulding going around the center panel, but it’s also on the door pieces and added to it’s size. The mouldings will have to be their own components as to not affect the door’s attributes.
I can’t see your new file because version 2015 (sorry). But in the previous model, I went into your component for handle, and there’s still a group inside (the handle), I locked it’s dimensions, and it works for me, stays the same size.
Keep trying, at some point, it’ll all click into place and you’ll get it working. And then maybe you’ll want to reorganize and redo it all
Cabinet Double 2.skp (245.8 KB)