In the following Excel table, the 2^nd column contains categories and the 3^rd column contains detail data:

We need to enter values in the same category in cells on the right of the grouping cell in order:

Use SPL XLL to enter the following formula:

=spl("=E(?).group@o(#2).(#1|#2|~.(#3))",A1:C8)

The E() function reads data in a stretch of cells as a table. group@o does not sort data before grouping. #1 is a simplified form and represents the 1^st column of the 1^st member in a group; and ~.(#3) means a sequence made up of values of the 3^rd column of a member in a group.

Source:https://stackoverflow.com/questions/78341823/how-to-make-the-duplicate-values-on-columns-as-1-row-in-excel