Enter Find Mode 
Set Field [Table::Date_1; 7/1/12...7/10/12]
Set Field [Table::Date_2; 7/1/12...7/10/12]
Set Error Capture [On]
Perform Find 
This will find records within the date range in both fields.
Multiple Find Requests
Answer ID: 5210Last Updated: Oct 20, 2011
Some FileMaker Pro owners may be familiar with database programs that require you to enter search requests using "and/or" logic. If you are trying to understand how to apply these techniques to FileMaker Pro, here are some guidelines to keep in mind:
• The Add New Request command lets you have more than one find request at a time. Add New Request shows up when you are in Find Mode and can be found under the Requests Menu. Multiple Find requests behave as "or" criteria. For example, suppose you have a database that contains a State field and you want to find all the records that contain "California" or "Hawaii."
1. Enter Find Mode.
2. Type "California" into the State field.
3. Select New Request from menu.
4. Type "Hawaii" into the State field.
5. Perform the Find.
You appear to have two date ranges:
Your criteria: S_dateBegin...S_DateEnd
You data: Date_1...Date_2
I think that you want to find all records in MyTable where Date_1...Date_2 overlaps the interval in S_dateBegin...S_DateEnd
If so, the date intervals can overlap three different ways:
Let's say S_dateBegin = July 1 and s_DateEnd = July 10.
1) S_dateBegin falls somewhere on the Date_1...Date_2 range.
Such as: Date_1 = June 1 and Date_2 = July 4
2) S_dateEnd falls within Date_1...Date_2
Such as Date_1 = July 3 and Date_2 = August 1
3) Criteria interval encloses entire Date_1...Date_2 range
Date_ 1 = June 20 Date_2 = July 30
A find will need 3 requests to find records in MyTable for all three forms of range overlap:
Enter Find Mode
Set Field [MyTable::Date_1 ; "<" & MyTable::S_DateBegin ]
Set Field [MyTable::Date_2 ; ">" & MyTable::S_DateBegin ]
Set Field [MyTable::Date_1 ; "<" & MyTable::S_DateEnd ]
Set Field [MyTable::Date_2 ; ">" & MyTable::S_DateEnd ]
Set Field [MyTable::Date_1 ; ">" & MyTable::S_DateBegin ]
Set Field [MyTable::Date_2 ; "<" & MyTable::S_DateEnd ]
Set Error Capture [on]
Perform Find 
Note: S_DateBegin and S_DateEnd must both have global storage specified. Date_1 and Date_2 must be of type date.
I was forgetting the line "New record/Request"