-tiuh.

Headword: 
-tiuh.
Principal English Translation: 

present of the purposive motion form away from the speaker, tīuh/-to.

James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 235.

Orthographic Variants: 
-tihui, -iuh
Lockhart’s Nahuatl as Written: 

auxiliary form of yauh, progressive, goes along doing. pl.
-tihuih.
James Lockhart, Nahuatl as Written: Lessons in Older Written Nahuatl, with Copious Examples and Texts (Stanford: Stanford University Press and UCLA Latin American Studies, 2001), 235.

Attestations from sources in English: 

(-ti + yauh) a progressive, purposive action, present tense.

moquetzinotiuh mahcopatlachialtilitiuh yhuã momanepanotzinotiuh = standing looking upward and crossing his arms (central Mexico, 1613)
Annals of His Time: Don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, James Lockhart, Susan Schroeder, and Doris Namala, eds. and transl. (Stanford: Stanford University Press, 2006), 242–3.