You are looking for a linear list of approvals. IF the list MUST be approved in a specific order, then the simplest way is an ordered junction table.
You have two main tables: your documents and your departments. If both tables have a usable prime key, then your solution is a third table that we call a junction. You will also need a users table that lets you track who did what to whom at any given time, a persons table perhaps. In that table, you would need a Department ID field showing which department the person represents, and perhaps 0 if this person can use the DB but doesn't have approval authority, only read-only / viewing authority.
DocDepJunction:
DocNum: Long, foreign key to Docs table
DepNum: Long, foreign key to Deps table
OrdNum: Long, shows the order in which the the approvals must occur: 1 must be first, 2 must be 2nd etc.
AppDate: Date, the date/time of the approval
AppPers: Long, foreign key to Persons table (representing who approved it)
You have one record in this table for each combination of document and department, so for a given document, you have N+1 records where N is the number of departments and the +1 is the "END department" entry that says you are done.
Now build a query that only shows the record with the LOWEST ordinal number because that record represents the department that must approve the document next.
Then you can build joins between the junction table and the other two tables. When a person logs in, you can query that list of "lowest ordinals" that have the person's department ID. That person can then review and approve as needed. Obviously, you will have a special value representing the "END" department, which doesn't need approval and would use that END department to make lists of documents that are fully approved.
For statuses, you can query this same junction for documents where the lowest available entry is the "END department" entry - and thus get a list of closed documents. Or you can make a query against the same table for cases where the lowest entry is NOT the "END department" thus seeing what is still pending approval (and implicitly, which department needs to approve it.)
This is just an idea, worth pursuing only if it makes sense to you. So I'll stop here for new and let you think about it.