In the practical project that I code for,this implement actually involves two independent tools:

1,Atlas material dependency check tool.
2,Show multiple FBXs' UVs tool.

First,I create an atlas material dependency check tool to find out all FBXs that refer to a selected atlas material,and select them all.

Second,artists can use the show multiple meshes's UVs tool to get a combination display of all selected FBXs.This gives them an idea of atlas texture efficiency.