Size of timeline in Photoshop

I have about 8 video clips in a group. There used to be a slider which allow you to zoom back in order to see all the clips. In other words shrink the entire line to view it. The slider used to be at the bottom left of the timeline screen. It is no longer there. What am I missing? I would like to zoom out to see all the clips that were off the screen and rearrange them.

windows 10, Latest version of Photoshop CC 16G ram

Thanks for replies as usual, the community has been a great help to me

[Moved out of the Community Help Application forum (which is for support of software Adobe used to make for creating documentation) and into a Photoshop support forum - moderator]