Solidworks - equations in assemblies and sub assemblies

Good morning.

Please, I need your help

1/ Assembly 1 - sideboard.sldasm

I have an assembly (1) with equations and global variables. In this assembly, all dimensions are managed with global variables.

For example, assembly 1 is a sideboard.

global variables are : sideboard_width, sideboard_depth, and so on...

sideboard assembly is saved.

2/ Assembly 2 - closet.sldasm

I have an assembly (2) with equations and global variables. In this assembly, all dimensions are managed with global variables.

For example, assembly 2 is a closet.

global variables are : closet_width, closet_depth, and so on...

3/ I insert one assembly component which is sideboard in closet assembly.

So closet assembly is composed of several parts and 1 assembly (sideboad).


How can I manage sideboard dimensions with closet global variables ?

I want, if closet width change that sideboard width change at the same time and proportionnally

For example : width_sideboard = closet_width - 30mm

Please, help me. Thanks a lot.