<div class="mat-select-value">
   <span class="mat-select-placeholder ng-tns-c34-170 ng-star-inserted">
   UniqueTextID
   </span>
</div>

"//span[contains(@class,'mat-select-placeholder ng-tns-c34-170 ng-star-inserted')][contains(text(),'UniqueTextID')]"

"//div[contains(@class,'mat-select-value')][contains(text(),'UniqueTextID')]"