Did you know in the New UI you can convert a search from the Contacts page into a segment? 

Why don't we go through the process together?

Go to the Contacts Management page by navigating to Contacts -> Search in the side menu (Fig 1). 

Fig 1

Click on the Databases button at the top to select which database's contacts you want to display (Fig 2). 

Fig 2

Once you've selected the database or datbases you want, click on Save to return to the Contacts page (Fig 3). 

Fig 3 

Now we should see all the contacts from the database listed. 

In the Search bar in the upper-right of the screen, type in a search term to narrow the contacts down (Fig 4). 

Fig 4

You can further refine you search by clicking on the Filters button in the upper-right (Fig 5). 

Fig 5

After configuring your filter, you can clicks the Save button to return back to the Contacts page (Fig 6). 

Fig 6

Now that your search and filter is all set up how you want it, let's click on the Save as segment button to the left (Fig 7). 

Fig 7

Now that the (Fig 8). 

Fig 8

Now that your Segment is saved. If you navigate over to the Segments page, we can see your new Segment added at the top ( Fig 9). 

Fig 9