I have the similar idea on my DB one field for a search of all fields in one table but you can probably use the same script I have created with adding a bit more to go through multitple tables. Bascially you should use "Loop" "End Loop" script steps. Email me your email address and I'll send you my script. NickT@capatrol.com
If you have defined relationships in Manage | Database | Relationships like this:
Parts:: Part Number = Bolts:: Part Numberfk
Parts:: Part Number = Clips:: Part Numberfk
You should be able to just place the datat fields from Bolts and Clips directly on your Parts layout and you can then put search criteria in these fields when performing a find.
Example: Use the Field tool to add a new field to your layout. Select Clips from the drop down and click Thickness to add the Thickness field to select it.