Parse Text in between characters in Excel

https://www.exceldemy.com/extract-text-from-a-cell-in-excel/#43_Extract_Text_between_Two_Specific_Characters_from_a_Cell_Using_the_MID_and_SEARCH_Functions

TEST15060_TZ-048_2013-07-01T10_17_08.xml

=MID(D2, SEARCH("_",D2) + 1, SEARCH("_",D2,SEARCH("_",D2)+1) - SEARCH("_",D2) - 1)

Returns:  TZ-048

The first text is in D2 in the Excel output for the Dose Return Name.  The formula is how you would extract the TZ-048 Unit from that text.