You may filter the list of available tags by the description with which they have been configured (i.e. the Description property configured in the tag properties folder for each tag).
1.
Click the Tag Selector button appearing in the Historical Data Viewer page's
tool bar. 
The Tag Selector dialog will open.
2. Enter one or more characters in the Filter by Description field. You may use a combination of characters and the asterisk wildcard character (*) to locate a specific tag by its configured description (e.g. "Well*" will find all tags whose description begins with "Well", or "*3*" will locate all tags whose description contains the number "3").
3. Press the Enter key on your keyboard to input the search characters.

The tags matching the name or characters you entered will be displayed in the Tag Selection list. You may now plot the located tag(s) adding them to the Selected Tags/Queries for Plotting list.
Note: To reset the Filter by Description field (thereby removing description filtering from the list), ensure that no characters are entered in it, and then press the Enter key on your keyboard.