For now, other site's meeting invitation is not displayed on Webex mobile app's calendar tab.
Please let it display on the mobile app's calendar tab so I can check my meetings by using a smartphone.
Are you referring to the Webex Meet mobile app or the Webex mobile app? What is your user's calendar platform (Microsoft Office 365, Google, Microsoft Exchange)?
If you are referring to the Webex mobile app (not Meet), and the user has not connected to the user's calendar system (e.g., Exchange, Exchange Online, Google) or on Local Calendars (iOS, iPadOS, Android) configured, then this already works today. We show meetings scheduled from any Site as long as the user's authenticated email address is the email address they were invited to.