I have a total of three Tables total but one is combining the two first
tables and adding more detail to the overall table.
T1. Account Groups:
Fields are-  Auto #:	Account Group:
1	Alpha
2	Bravo
3	Charlie
4	Delta
T2. Account Types:
Auto #   Account Group:		Account Type:
(This is a drop down		(text box)
pulled from above table)
1	Alpha	                                 IT support
2	Charlie	                                 Pricing
3	Bravo	                                 Maintenance
4	Alpha	                                 Security
5	Delta	                                 Facility
6	Alpha	                                 Pricing
		
		
	 
It sounds like you're another victim of Microsoft's misdesigned, misleading,
monstrous Lookup Field misfeature. See
http://www.mvps.org/access/lookupfields.htm
for a critique. The Account Group in your T2 APPEARS to contain "Alpha" but it
does not; it actually contains 1 - a numeric link to T1's primary key.
	
	
		
		
			T3. Main Account info.:
Auto #:  Account Group:         Account Type:                     Name:
Work location:
(Both are pulled from table 1 & table 2)
Alpha	           IT support	                    Jeff Smith	1
2	Charlie	           Pricing	                    Amy Jones	2
3	Bravo	          Maintenance	                    Joe Backer	1
4	Alpha	          Security	                    Mike Keller	1
5	Delta	          Facility	                    Jan Johnson	2
6	Alpha	          IT support	                    John Doe	1
		
		
	 
Same applies. The Account Type is actually storing a number (e.g. you see
"Pricing" but what's stored is 6.
	
	
		
		
			When I add a new person to my form and select ….Alpha from my Account Group
(drop down box) I would like my Account Type to only show those options that
fall under that Account Group. (Example: Alpha) (Result: Only the choices IT
support, Security & Pricing show up)
		
		
	 
You can do this on a Form very easily. AFAIK you cannot do it in a table. Bind
a combo box to the Account Type field, based - not on your T3 - but on a Query
such as
SELECT [AccountTypeID], [Account Type] FROM T2 WHERE T2.[Account Group] =
Forms!YourFormName!YourFirstComboName ORDER BY [Account Type];
You'll need to adjust field and table names of course. You will also need to
Requery this combo box in the afterupdate event of the first combo.
	
	
		
		
			I would also like to apply this to a multi selection search or filter form.
I hope this is enough information.
		
		
	 
Well, a bit more info about what you mean by a "multi selection search or
filter form" would help. Multiselect listboxes can be used for searching but
it's a bit clumsy and requires some VBA code.