The object could be a subform with its own object: Forms!mainform!subform!objectname.
Unless I misunderstand the meaning, this is incorrect. To refer to a control on a subform, you have to sequence from the forms collection > main form > subform control > Form object of the subform control, then you can refer to an object on the subform. Subform control name is not the the name of the subform, although Access often uses the subform name for the control if you use a form wizard. I will use the wizards for speed, but always go through and fix the names to avoid ambiguity, such as controls and fields being named the same.
Code:
[Forms]![Main form name]![subform control name].[Form]![control name on subform]
To refer to a subform property, I use a different notation since I found the above syntax didn't seem to work
Code:
Forms("MainFormName").Controls("subformControlName").Form.Recordset.Recordcount
As an aside, I'm wondering about the design of your form(s). To have a tab for each department does not seem right. As an example, any time a department is added/eliminated/renamed or whatever, that necessitates a design change (such as adding/eliminating/renaming tabs) is bad practice.
The more we hear silence, the more we begin to think about our value in this universe.
Paraphrase of Professor Brian Cox.