I haven't found an easy solution. I do however know what's causing it. See my answer here: https://answers.splunk.com/answers/770813/splunk-time-selector-being-compressed-in-google-ch.html#an...
It's caused by
overflow-x:hidden for the css style
.shared-timerangepicker-dialog .presets-container .presets-group li, but I can't find a way to modify it. The value should be
See pictures to demonstrate:
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