Question about geographic segmentation

Question about geographic segmentation

I'm trying to do geo-segmentation for one of my campaigns. I would like to, for example, limit a campaign to an area roughly 30km radius of a city. I don't see an option for that specifically, but I see that I can perform the segmentation by filtering only those postal codes within a 30km radius. I can get this information from a site like:
https://www.freemaptools.com/find-zip-codes-inside-radius.htm

My problem is that zoho only lets me enter 6 criteria. If I have 15 postal codes, is there some syntax that I'm missing to work around this? Perhaps using comma delimiter and putting all 15 codes in the first line?
[Field] contains {postalcode1,postalcode2,postalcode3...postalcode15}

Any other workaround for geographic segmentation I might be missing?

Thanks