Do you mean, for example, in a Google Sheet each row is a task, when people update the task in Asana it updates the Google Sheet; when people update the Google Sheet, it updates Asana?
I don’t know of anything that is point and click. But it can be done with Zapier Zapier
or writing scripts Here’s an example
Depending on your use case/scenario, we are working on an integration (not a Google Sheet) that may help (its more for Project Managers, Designers, Developers who are collaborating on web projects
It lets you markup anything in a web browser, with virtual post-it notes that create tasks in Asana. Its a 2 way sync, so stakeholders, clients, team members can view, comment, change status, etc inside Asana, and watch as the notes update. https://getsifta.com