When you create a custom field, one of the custom fields types is 'Tags'. You can use this to enter information as a tag. For example, to have employees enter their hobbies.
You could then use these tags as a filter on your company page. For example, you could filter your employees by those with an interest in Football.
This may be more useful to use than a multi-select custom field type. Multi-select requires you to have options already listed to choose from, whereas tags provide flexibility to write your own entry.
Create a tag custom field
Enter a tag on an employee profile
When on your profile or an employee's profile, scroll down to the relevant custom field.
This will be either on the Employee or Personal tab.
In our example, this is a 'Hobbies' field.
In the field, type in your hobby.
When you press the Enter key, a tag appears above.
Once entered, make sure you click Save.