You may want to add a contact to multiple opportunities. Follow these steps to learn how to allow duplicate opportunities. After that is done, there are two ways to add them: you can add an opportunity in the individual contact's profile, or use the Opportunity Trigger Action.
Step 1: How to Allow Duplicate Opportunities in Settings
Under Settings > Business Info, navigate to "General"
Check the box for "Allow Duplicate Opportunity."
Step 2: How To Allow Duplicate Opportunities Using the Opportunity Trigger Action
Click into the trigger.
Toggle on the opportunity trigger action which allows the lead to be in multiple opportunities.
Click Save to confirm your changes.
NOTE: This will only put them into a duplicate opportunity if it is in a different pipeline that they were not previously a part of.
Step 3: How to Add Opportunities in the Contact profile.
Click into the contact profile.
Scroll down to the left side where you see "Opportunities". Here, you can place them in however many you'd like.