lemon14 To speak to your example, a longer tenure at one company is preferred, however it's best that you show a promotion if you've worked there for three years. If you need to "move out to move up" then so be it - that is common. Job hopping every year isn't ideal, however in places like Silicon Valley, it is actually quite standard.
We often forget that the adcom doesn't really care about your jobs, but what your overall career, trajectory and contributions
say about you. What kind of person are you, what potential do you show, do they want you in their club? Choose jobs that will allow you to showcase leadership, teamwork and problem solving. Focus on demonstrating that you have these qualities via accomplishments in the resume, no matter where or in what context.
One last bit, it's nice to have hot brand names of MNCs on your resume. It shows endorsement of you for sure. However there is also something to be said for working on a higher level at a startup or smaller company. If you work at a huge company, it's understood that your scope will be more narrow and vice versa.
Hope this helps!