Multiple Entry to Schengen over three years

For work, I need to travel for work to Netherlands,Italy, Germany and Portugal (first visit) across the next three years. I might need to spend 6 months in Germany but i will be spending less than 2 weeks in the other countries. I hold a Global Talent Visa, is there a possibility to get 'MULT' visa while also spenidng this much time in germany (which is more than 90 days). Is it possible I can exit and enter four seperate times? essentialy what I'm asking is, which is my best option?