When first opened, the palette shows a limited list of character categories, and it defaults to ‘Smileys & People’ emoji. Serious users of text will want to customise the list of character categories by clicking on the ⚙ (‘gear’) dropdown menu.

Note that you could also just key any Unicode hex scalar value in the ‘Search’ box, hit Return, and directly go to the character that is sought.

At the bottom of the list come the Code Tables. Clicking on the triangle will reveal several encodings, the first and most important of which is ‘Unicode’. Checkmark that.

In the left-hand column you can now directly select ‘Unicode’, and in the middle column the top pane lets you scroll down all Unicode ranges.

The middle bottom pane shows the contents of the Unicode range selected in the top middle pane. In this case, it is the first Unicode range that has five-digit hexadecimal scalar values, which you could not access by using the Unicode Hex Input.

Double-clicking any character will insert that character at the insertion point in any text application that is active (= whose window is topmost next to the Character Viewer palette).

You can drag column/pane boundaries to enlarge any panes that need it, for instance the middle bottom pane with all the characters.

You could scroll down all the way to 0002B820 to get to the Unicode range ‘CJK Unified Ideographs Ext. E’, and then scroll down in the bottom middle pane to search for a character you might need, e.g. U+2CC5F.

But you could also just key ‘2cc5f’ in the ‘Search’ box to quickly access the character you need.

BTW, the ‘Search’ box also accepts (parts of) Unicode character names, so that is also a very useful method of finding a character, maybe when you know its name but not its code.