References View uses several visual cues to communicate the status of the SolidWorks files and their relationship to other items in the assembly.
References view displays SolidWorks files in a tree structure, with each node representing a part, assembly, or drawing. When you open the Tree View window from n!Fuze in Reference view mode, the initial view displays the only the SolidWorks file for which the tool was launched (bordered in a gold color) and its parent assembly (bordered in a gray color). When you click any node, it turns blue.
Parent/child relationships are represented top to bottom, with parents shown above the children in the Tree View window.
Initially any nodes of the tree are displayed in a collapsed state. You can use the Expand button to expand or collapse one or all child levels.

Click + or - to expand or collapse the next child level, or All to expand all child levels of the selected node.