Etymology of 此 cǐ this, these? What is the etymology of cǐ ? How this character means those, these?
《說文》：「此，止也。从止从匕。匕，相比次也。凡此之屬皆从此。」

甲金文從「止」從「人」，左右結構與上下結構無別。象人所止步之處，即此處之意，與「彼」相對。

陳初生以為「以腳趾與一側身人形會腳步到此停止之意。」何琳儀以為會以足蹋人之意，「跐」之初文。姑備一說。

此 is a compound ideogram comprising 止 and 人 (匕 is a crouching man). One always infers the combined meaning of the two simpler, juxtaposed pictograms.
Multi-function Chinese Character Database adopts the explanation of the scholar Chen Chusheng: With 止 being a pictogram for 'foot' at first and later a phonetic loan for 'to stop', the explanation for the meaning of 此 is believed to be that a man (人) arrives 'here' when he stops (phonetic loan 止) his pace (pictogram 止). 'This' and 'these' are derived meanings of 'here', which is understandably figurative.
Shuowen Jiezi however argues 'to stop' comes from the character 匕. Being one of the two 'rotated' men in 比, a man stops to compare (meaning of 比) himself with another. This is in accordance to Duan Yucai's annotation 相比次而止也.