I think you need to add a new method in LanguageService.fs. The method will only work correctly if files are saved.

```
  /// Get all the uses in the project of a symbol in the given file (using 'source' as the source for the file)
  member x.GetUsesOfSymbolInProjectAtLocationInFile(projectFilename, fileName, source, files, line:int, col, lineStr, args, targetFramework) =
   async { 
    match FSharp.CompilerBinding.Parsing.findLongIdents(col, lineStr) with 
    | Some(colu, identIsland) ->

        let! checkResults = x.GetTypedParseResultAsync(projectFilename, fileName, source, files, args, stale= AllowStaleResults.MatchingSource, targetFramework=targetFramework)

        match checkResults.GetSymbolAtLocation(line, colu, lineStr, identIsland) with
        | Some symbol ->
            let lastIdent = Seq.last identIsland
            let projectOptions = x.GetCheckerOptions(fileName, projectFilename, source, files, args, targetFramework)
            let! projectResults = checker.ParseAndCheckProject(projectOptions) 
            let refs = projectResults.GetUsesOfSymbol(symbol)
            return Some(lastIdent, refs)
        | None -> return None
    | None -> return None 
   }

```