firebase - list only items you have access to -

background

i have set of items user may append to, may read/write items own.

this simplified version of i'm working on. can't make $uid part of path because these items shared specific other users.

"session": {   "$other": {     ".validate": "(!data.child('owner').exists() && newdata.child('owner').val() == auth.uid) || newdata.child('owner').val() == data.child('owner').val()",     ".read": "data.child('owner').val() == auth.uid",     ".write": "newdata.child('owner').val() == auth.uid"   } } 

given above rules user may push({ owner: my_uid }) list. have verified user may read , write newly created record.

question

how can user find of records has access to?

"session": {   "index": {     "$uid": {       ".read": "$uid == auth.uid",       "$sessionid": {         ".write": true       }     }   },   "$other": {     ".validate": "(!data.child('owner').exists() && newdata.child('owner').val() == auth.uid) || newdata.child('owner').val() == data.child('owner').val()",     ".read": "data.child('owner').val() == auth.uid",     ".write": "newdata.child('owner').val() == auth.uid"   } } 

with approach every time create session/<id>/ create entry under session/index/<uid>/<id>. because user can write address, can read should able share user writing index.