Multi-value User columns vs Native Refinement

Question

Following Scenario:

• SiteColumn called "MultiUser" with type User, allowing multiple values.
• MultiUser added to a Library

• Multiple users added per item e.g.:

  [Title]   [MultiUser]
  Item1     Mike; Marc; Tom
  Item2     Marc; Björk
  

• Add a managed property "MultiUserMP" with type text and mapping to crawled property "ows_MultiUser" allowing multiple values

• Full crawl

Problem: Unfortunately, the multi-value column is not represented in the refinement result table! Meaning that the refinement table is not:

    [RefinementName]   [Count]
    "Mike"             1
    "Marc"             2
    "Tom"              1
    "Björk"            1

but:

    [RefinementName]   [Count]
    "Mike; Marc; Tom"  1
    "Marc; Björk"      1

This seems to happen only for "User or Group" columns. Refiners for multi-value Choice, Lookup, and Managed Metadata columns are calculated correctly...

NB: If the "User or Group" column is added as a Site Column, SharePoint creates an own Crawled and Managed Property. The managed property is postfixed with "OWSUSER" and contains an enhanced user representation (i.e. not only the display name of the user, but an OWS-User String of following format: "eMail-Address | DisplayName | EncodedClaimsName ClaimsName")

Answer 1

Maye this will be a help for others: We worked around that, by implementing an own Content Enrichment Web Services, that takes the strings and splits them by ; to multiple values...

Answer 2

I also faced this problem. I created a work around by creating a new display template.

SharePoint 2013 multi people refiner showing as a single line with semicolumns