Hi Josh,

If the same field is present in multiple templates you can simply search on that field individually. This will bring back any result matching the date range you put in, regardless of template.

However, it sounds like you instead have multiple separate fields that store destruction dates. If this is the case, you can use advanced search syntax to return all entries that have the date range you want in either field A, or field B, or field C, etc. This search, for example, would pull back all documents with a value of today's date or before in either of two fields (Destruction Date or Destruction Date 2). 

                    {[]:[Destruction Date] <="09/10/2014"}|{[]:[Destruction Date 2] <="09/10/2014"}

When working with advanced search syntax, a great place to start is by running a search that's close to what you want with the Advanced Search option displayed as well. This will allow you to see what syntax is being used for the search you ran. From there you can use what was generated as a starting point for your own modifications. You can read more about advanced search syntax in the Laserfiche Advanced Search Syntax whitepaper.