@DrVeeVah when adding multiselct field to a search result, you are basically doing a join, meaning, that you results will multiply as the number of selected elements in the multiselect. So, you will have to set the other fields as group, and for the multiselect field you have to set a formula (max) and set the formula to be NS_CONCAT({multiplesekect field id}). It will result in a concatenated string of all the selected value.