
There is no need to use multiple queries. You can use a single query as the RecordSource property of the second form, and include multiple parameters in it to restrict the records returned in the form.
You might like to take a look at DatabaseBasics.zip in my Dropbox public databases folder at:
In this little demo file the first form in the section on 'retrieving data from the database' includes three unbound subforms illustrating different types od searches. That on the right allows you to select up to two parameters in combo boxes, but it could easily be extended to include more controls for entering/selecting other parameters.
In the demo a report is opened to return the results, but a form can be opened in exactly the same way. The report's RecordSource is the following query which references the two combo boxes in the subform:
SELECT [FirstName] && " " && [LastName] AS FullName, Address, City, Region,
Country, Employer, LastName, FirstName, Contacts.ContactID
FROM (Countries INNER JOIN Regions ON Countries.CountryID = Regions.CountryID)
INNER JOIN (Employers INNER JOIN ((Cities INNER JOIN Contacts
ON Cities.CityID = Contacts.CityID) INNER JOIN ContactEmployers
ON Contacts.ContactID = ContactEmployers.ContactID)
ON Employers.EmployerID = ContactEmployers.EmployerID)
ON Regions.RegionID = Cities.RegionID
WHERE (Cities.CityID = Forms!frmReportDialogue!cboCity
OR Forms!frmReportDialogue!cboCity IS NULL)
AND (Employers.EmployerID = Forms!frmReportDialogue!cboEmployer
OR Forms!frmReportDialogue!cboEmployer IS NULL);
By examining the parameters for OR IS NULL this allows the user to enter/select values in as few or as many of the controls in the subform as necessary. The option for combining the parameters with AND or OR is given. The above query uses the AND operator, so those rows which match both parameters are returned. If the OR option is selected rows which match either of the parameters would be returned.
The other subforms in the same form in the demo illustrate two methods for using a multi-select list box to restrict the results by multiple values in the same column (field).