DMN16 — FEEL descendants operator

In some decision models, the input data must conform to an industry-standard xml schema in which elements of interest are many levels deep. Converting such a schema directly to a FEEL item definition requires very long path references. The xpath language has a descendants operator that significantly shortens the path expression. I propose a similar operator (or, less ideally, a function) for FEEL.

An example is MISMO from the Mortgage Bankers Association. In home appraisals, one item of interest is the Appraiser. To reference the Appraiser from the FEEL item definition generated from the xsd requires this:
MESSAGE.DOCUMENT_SETS.DOCUMENT_SET.DOCUMENTS.DOCUMENT.DEAL_SETS.DEAL_SET.DEALS.DEAL.SERVICES.SERVICE.VALUATION.VALUATION_RESPONSE.VALUATION_ANALYSES.VALUATION_ANALYSIS.PARTIES.PARTY[ROLES.ROLE.ROLE_DETAIL.PartyRoleType="Appraiser"][1]

In xpath, omitting namespace prefixes, the descendants operator // simplifies this considerably:
MESSAGE//PARTY[.//PartyRoleType='Appraiser']

If // were used as a FEEL descendants operator, you would need only
MESSAGE//PARTY//PartyRoleType="Appraiser"[1]

To get the Appraiser's name, instead of
MESSAGE.DOCUMENT_SETS.DOCUMENT_SET.DOCUMENTS.DOCUMENT.DEAL_SETS.DEAL_SET.DEALS.DEAL.SERVICES.SERVICE.VALUATION.VALUATION_RESPONSE.VALUATION_ANALYSES.VALUATION_ANALYSIS.PARTIES.PARTY[ROLES.ROLE.ROLE_DETAIL.PartyRoleType="Appraiser"].INDIVIDUAL.NAME[1]

you would need only

MESSAGE//PARTY//PartyRoleType="Appraiser"//NAME[1]

Add a descendent operator to the FEEL grammar

Add a descendant operator in the FEEL grammar that is similar to a path expression but uses 3 dots (...) instead of one.