Here's a screenshot of something I'm currently working on. I decided to use tabs at the top because filling in the "Office Details" is just as important as the list of employees and because in the future it could expand into other tabs, such as "Stats" for example.
The Details tab includes information that will be used to create all kinds of CSV reports, but once it's completed at the beginning of the year, it doesn't get accessed as often.
My problem is that the "Period" and "Filter" inside the sidebar, as well as the "New Employee" button at the top only affect the "Office Employees" tab. The "Other Offices" list is useful for both.
I tried cramming everything inside that tab, the period and filter as selects above the table of employees, but it just didn't work.
Any ideas on how to get this layout to make more sense?