A three-fold loop (agemaki musubi 総角結び) was a particular method of tying himo belts that left loops to the left, right and above the knot, rather like a clover leaf. In his poem, though, Sanekata is referring to a well known popular song (saibara 催馬楽) of the same title:

あげまきや
ひろばかりや
離りて寢たれども
まろびあひけり
か寄りあひかり