We started using the new Help Value Services and I think it's great as you can directly use the ABAP value help and don't need to wrap it within an extra web service or similar work arounds.
Here are some useful links regarding this topic:
- Value Help in SAP Process Orchestration
- BPM OData Service for Accessing Value Help - Modeling Processes with Process Composer - SAP Library
- Providing Value Help Using BPM API - Modeling Processes with Process Composer - SAP Library
- Configuring Alias for Providing Value Help in the Task UI - Modeling Processes with Process Composer - SAP Library
However, I had little trouble using filters.
There is no problem using only one filter - you can go the way descibed in the SAP Help. But when I was supposed to set multiple filter, I was not able to find an example and it is not straight forward as it is not the default OData filter syntax. The solution: you have to provide the filters in the url semicolon separated:
http://<host>:<port>/bpmodata/valuehelp.svc/<AliasName>/HelpValues? filter=<filterAliasName>:<filter value>,operation(EQ|CP|LT|NE|LT|LE|GE|GT);<filterAliasName>:<filter value>,operation(EQ|CP|LT|NE|LT|LE|GE|GT);<filterAliasName>:<filter value>,operation(EQ|CP|LT|NE|LT|LE|GE|GT)