Set var based on regex?

I’m currently collecting disk usage data on EBS volumes across our farm and would like to trim down the path field to a portion of the string for my alert message. I haven’t been able to find anything in the docs for a way to do this, and am unsure its possible. As an example, given this data point:

> select * from disk where path =~ /rexray\/volumes/ limit 1
{
    "results": [
        {
            "series": [
                {
                    "name": "disk",
                    "columns": [
                        "time",
                        "device",
                        "free",
                        "fstype",
                        "host",
                        "inodes_free",
                        "inodes_total",
                        "inodes_used",
                        "path",
                        "total",
                        "used",
                        "used_percent"
                    ],
                    "values": [
                        [
                            1510339730000000000,
                            "xvdf",
                            15842684928,
                            "ext4",
                            "ip-xx-xx-xx-xx",
                            1046884,
                            1048576,
                            1692,
                            "/var/lib/docker/plugins/27f131b49545cc98d7320ff5478b218564629f2e7a29728d7570f4204211a610/rootfs/var/lib/rexray/volumes/service.volume.name",
                            16776032256,
                            57577472,
                            0.3621164893479997
                        ]
                    ]
                }
            ]
        }
    ]
}

I would like to be able to parse out the path value here i.e. "/var/lib/docker/plugins/27f131b49545cc98d7320ff5478b218564629f2e7a29728d7570f4204211a610/rootfs/var/lib/rexray/volumes/volume.name" and only keep the last part of the value. Is there a way to set a var based on a regex? I’d like to run a regex similar to /([^/]+$)/g against path which would set the value to volume.name