I am not sure I understand...but here is another guess.
I am assuming that you have a # of fields in the one query and on each tab you only have a portion of those fields, then by choosing a specific value in the combobox you want some of the data to not be filled in or you want only the record/data for one record to show up?
If you have all of the fields in your query and you don't care if the labels/fields show up on each tab, but just don't want the actual data showing up in them, then one idea would be to set a code in the combobox's after update event and possibly in the form's on-current event that says something like:
If Me.comboboxname="value" then
Me.textboxname.ControlSource = "" 'not connected to table field
Else
Me.textboxname.ControlSource=[Table Field Name] 'connected to table field
End If
You could add multiple fields and variations to this If/Then statement to make other fields look empty. You can also make different tabs visible or not in the same if/then statement.
Or If you have a combobox that queries so that only a specific record/data shows up and all of the data for all records are still there, then the query criteria may not be phrased correctly or the combobox name may be misspelled... When you open the query separate from the form and put in the required combobox values, are the results correct?
Sometimes, I have had better luck when I have made separate forms, each based on a query that has fields and criteria specific to that form instead of an all fields in one query
For example, if I had a form with a tab control where Contact info is on one tab, the Training info is on another tab, the Position info is on yet another one and I had a combo box on each tab to aid in pulling the correct information - then I would make separate queries for each based on the value from that tab's specific combo box.
It might help if you gave a brief description of what type of fields you have one each tab and which ones you don't want to have filled in if the combobox is an example value. Also what criteria you are using for the query.
Others may be able to respond better than I...