Hi @Jane_Onwuchekwa ,
What is criteria to group a & b into index 1 likewise c & d to 2 ? If you have column which defines these grouping already then you can use rank function something like
rank([col1 ASC], [col2],PRE_FILTER)
I have created one approach for you to take a look.
SerialNo
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In case you need further assistance with your problem, please create a sample dashboard with sample dataset showing your problem state using Arena and post it here.(Details on using Arena can be found here - QuickSight Arena )
Please let us know if this is helpful.