Check multiple arrays for value without knowing parent node(s)

[mrsampson]

The structure of JSON in my log events is roughly as follows

{
    "Info": {
        "Apps": {
            "ReportingServices": {
                "ReportTags": [
                    "Tag1"
                ],
                "UserTags": [
                    "Tag2",
                    "Tag3"
                ]
            },
            "MessageQueue": {
                "ReportTags": [
                    "Tag1",
                    "Tag4"
                ],
                "UserTags": [
                    "Tag3",
                    "Tag4",
                    "Tag5"
                ]
            },
            "Frontend": {
                "ClientTags": [
                    "Tag12",
                    "Tag47"
                ]
            }
        }
    }
}

The number of fields in "Apps" is unknown, as are their names. Given this structure I need to check if a given tag ("Tag1", "Tag2", ...) exists in in a given array ("ReportTags", "UserTags", [..]), regardless of parent. If it does, I need the distinct names of parent field names that contain this.
Example 1: The input to the query is "ReportTags" and "Tag1". I'd expect it to output both "ReportingServices" and "MessageQueue" because both of them contain a "ReportTags" array that contains "Tag1".
Example 2: The input to the query is "UserTags" and "Tag5". I'd expect it to output only "MessageQueue" because only this one contains a "UserTags" array that contains this "Tag5".

I have looked at various questions on this forum, tried various combinations of mvexpand and such but I have not been able to write a query that does exactly this. Any hints and/or help would be greatly appreciated.

[ITWhisperer]

Something like this?

| spath
| foreach *.ReportTags*
    [| eval fields=if(isnotnull(mvfind('<<FIELD>>',"Tag1")), if(isnull(fields),"<<MATCHSEG1>>",mvappend(fields,"<<MATCHSEG1>>")), fields)]