Enhance list representation with simple database functions for sorting

Representation of the list can be flattened or in categories by presenting the records in the requested manner. Is it possible for a list that is categorized to  be presented as a flattened list without losing the information on categorization?

Here is the use case for a file with entries listed in categories: credit cards  online accounts, financial, etc  

1. View the list in a flattened manner

2. Sort list by name, last modified date or other fields.

3. Revert back to a categorized view by group. 

The windows version of password safe available on source forge uses the same file format and does all this. I have not been able to determine if this functionality already exists in your distribution. 

I find such a function will be useful in handling merging of files from different computers based on sorting modified date, determination of duplicate entries based on sorting by name etc. After the flattened list is processed, reversion to nesting by group can be used.