Use this API to append dimension members in Master and Analytic models. You can load Display Label as an optional parameter.
POST /modeling/model/member/append HTTP/1.1
Content-Type: application/xml
Accept: application/xml
X-ACCESS-TOKEN:
<?xml version="1.0" encoding="UTF-8"?>
<append-member-payload>
<model-name>$ModelName</model-name>
<dimension-name>$DimensionName</dimension-name>
<delimiter>$Delimiter</delimiter>
<hierarchy>$ParentChildHierarchyPlusOperatorLabel</hierarchy>
<dimension-member>$DimensionMemberPlusOperatorLabel</dimension-member>
… add more dimension members if needed
</append-member-payload>