VBA Function To Search Partial String And Return Value?

I'm trying to come up with a VBA function that would return cell values based on another cell value.

I can do this by comparing a range (column of cells) with the cell value to match and then return the value of the cell next to it.

For instance,

The function should search a column for partial text, as follows:

TS ID
PDT ID

TS 1.1
PDT 1

TS 1.2
PDT 2

TS 1.3
PDT 3

TS 2.1
PDT 4

TS 2.2
PDT 5

TS 3.1
PDT 6

TS 3.2
PDT 7

In the above table, the function should for partial text and return string as follows:

TS covered
PDTs

TS 1.1, TS 1.2, TS 1.3
PDT 1, PDT 2, PDT 3

TS 2.1, TS 2.2
PDT 4, PDT 5

TS 3.1, TS 3.2
PDT 6, PDT 7

So basically I am searching for partial text TS 1. and so on