is each line a separate Notes Document? and each document would be related to an employee? If this is the case then I would consider reading all leave requests for a given employee into something like a Java method that would evaluate the dates and return a Scope variable of a class of leaveRequest that would define all of the fields values from the Notes Document/s that match the date range. Now from that build your timesheet or whatever. Then use the returned value/s in a repeat control.

I'm not entirely sure I understand what is happening.

If this is a newly built application, then maybe it's not too late to add an extra field (let's call it "leaveMonths"). This "leaveMonths" field will store text value like following (from your first example):

If this is an existing application, then I'd suggest you just write a simple LS agent to insert the leaveMonths to each existing Timesheet document.

Once the above is done, create a Notes View which the first column is the leaveMonths (make sure it's categorized and sorted).

Then, on your viewpanel, compute the "Filter by category name" with the value for example "viewScope.selectedMonths".

And finally I assume you page should have the following 3 controls:

The above is how I would approach the problem if my understanding is right. I didn't do an actual test. Although I'm not quite sure why on one situation you can select just 1 month (July) and on another situation you can select 2 months (August and September). Will there be another situation where you can select 3 months, 4 months, and so on? If the no. of months you can select varies then maybe my approach is not suitable.

Thank you all,

I have done the first method what Mr. Carl Tyler said, Because this is exactly i am looking for.

Explode your date range, get the months, then get the unique months.

Then from the view column category I used the technique of  Show multiple value as separate entries.

But I don't know how it will affect the performance of the application ?