LinkedIn – What is the Search Limit?

You can control who can send you invitations.

From the Help Center:

Controlling Who Can Send You Invitations

You can select who can send you invitations from the Communications tab of the Privacy & Settings page. You'll receive a notification each time a LinkedIn member invites you to connect.

Select one of the following preferences:

1. Anyone on LinkedIn (Recommended)
2. Only people who know your email address or appear in your "Imported Contacts" list
3. Only people who appear in your "Imported Contacts" list

Note: If you select one of the last two options above, go to the Add Connections page to make sure your Imported Contacts list is up to date.

Invitations that don't meet your preferences will appear in your blocked invitations list.

1. Click on the Search button

2. Then Select the past company on the right side bar:

   

3. Based on your selection, you will see the list of people updating.