Sort by taxonomy weight I have a content type 'Member' with a field referring to taxonomy term called 'Member role' which is a multi value field. Each member may have up to 3 member roles. 

I have created a view to display members which sorted by taxonomy term weight with reference to taxonomy field. But the problem is each member repeats 3 times in the view result page. 

My question is how to remove duplicates and only sort by last value in the multi value field(Member role).
Below are a couple of things you can try to reduce duplicates caused by a multi-value field. Results will vary depending on your particular view.

1. Use aggregation

Under "Other" in Advanced options, enable Use aggregation.

Locate the offending field under "Sort criteria". Click on Aggregration settings, then select Aggregation type: Maximum.

2. Filter by delta

Under "Filter criteria", add the delta equivalent of your multi-value field; e.g. if your field is "field_artist_bio", there should be another field available called "field_artist_bio:delta". 

Add the field. Set Operator: is equal to, Value: 0.