我这儿 / 你那儿 / 他那儿 are northern Mandarin location pronouns: pronouns plus 这儿/那儿 turn a person into a place ('at mine', 'at yours', 'at his'). Standard in Beijing speech.
grammar
Note 这儿 is read zhèr — a single syllable with -er suffix. Don't pronounce it as zhè ér.
