Please go through the attached screenshot, for DSI_TE & DSI_RESET should be connect with Pin PB11 & PF10 Respectively in case of STM32F769IITx or LQFP176 package.
Load the Data Sheet, and use the *FIND* function on the text "DSI_TE" to observed the pins on to which that signal can be muxed/escaped. You'll find them in the pin list, and also the AF muxing tables.