I have two custom objects Member and Interest.

Note: From the child object create Master Detail field.

I want Interest Object to be the child of Member object, so that each member can have multiple interests.

To achieve this, follow the below steps

1.  Go to Interest object.

2. Go to Custom Fields & Relationships section.

3. Click “New” button.

4. Select “Master-Detail Relationship”.

5. Click “Next” button.

6. Select Member object in “Related To” field.

7. Click “Next” button.

8.  Fill the required details.

9. Click “Next” button.

10. Since it is Master-Detail relationship, the field should be visible to all profiles.

11. Click “Next” button.

12. Click “Next” button.

13. Click “Save” button.

14. Go to objects and check whether Master Detail relationship has been implemented successfully.