You can search labels, list them in one place, and find all issues by label.
View all labels in one place (globally)
You can list and administer all labels in Jira system wide affecting all projects.
To do so, go to Jira top navigation and find Manage Labels.
Please note that this feature needs admin or global permissions. If you do not see Manage Labels tab, it is likely that you do not have permission. Please ask your admin for access rights.
If you are admin or have correct permissions, it should look like below:
Need to search issues by label to see what in issues a label used? Just click on View filter, and it will show a Jira filter with all the issues under a label.
View all labels in one place (per project)
In order to view all labels and number of issues under a specific label, click on Manage Labels tab on left sidebar in your Jira project.
Find label usage and search all issues by label
You can simply search specific labels, sort labels by number of issues or alphabetically and quickly understand how they are used.
To find issues by label, click on view issues link, which will list all issues tagged with this label.