Schema Design for my use case(Nodejs+Mongo)

Hi, I want to implement a idea , for which i am confused with how to design the mongo so that it will be easy to write in nodejs. Here is my use case: 1. There will be multiple companies , say company A and B. 2. Each companies will have some no. of employees. 3. i want to create single app for all these companies. 4. i will have 5 type of task (say C1,C2,C3 etc)categories and each category will have multiple tasks (say C1T1,C1T2,C1T3 etc) to do. which i want to show to the users of respective companies. 5. Each category will have some fixed interval , in which there tasks will changed from server. say C1 all tasks has every monday interval , so each monday they will have new tasks otherwise old task. 6. if company A signedup earlier and Company B , later ,.... bt company A is seeing T3 so for company B , we want to start with T1.. 7. database is mongodb and api is in nodejs... lets discuss , how we gonna organise this database structure. we first need to define schema only... no coding. will pay for this thinking exercise.