You can select clip proxies and segments separately in the Timing View.
To select a clip in the Timing View:
The clip's proxy and track in the Timing View are highlighted by an orange bounding box.
Select a segment by clicking on it in the Timing View. When you select a segment in a track, it is highlighted in yellow.
Different types of selections can occur simultaneously in Timing View. You can select a segment and you can select a clip. The segment selection can be in a different clip than the clip selection.
(a) Proxy of selected clip (b) Clip selection (c) Segment selection
Image courtesy of Das Werk and The House