How to have 'Blanks' (in filter) appear on top

Filtering doesn't change the order of records. They're in the same order they were before filtering.

Before

	A	B
1	Hdr1	Hdr2
2	1	3
3	2	4
4	3	1
5	4
6	5	1
7	6	1
8	7	3
9	8	2
10	9
11	10	2
12	11	4
13	12	1
14	13
15	14	5
16	15	4
17	16	3

After filtering col B for 4s and blanks,

	A	B
1	Hdr1	Hdr2
3	2	4
5	4
10	9
12	11	4
14	13
16	15	4

I can't open your attachment.

I assume you mean by sorting, not filtering. Excel always sorts blanks to the bottom of a list, irrespective of sort order.

You would need to add a column that test the column of interest for a blank and return a values that causes those rows to sort to the top. Then do a two-way sort with that as the primary column.