Filtering a field is particularly helpful when you have a large amount of source data but you want to focus on specific areas.
1	Filtering	filter	VERB	ING	Tense=Pres|VerbForm=Part	6	csubj	_	_
2	a	a	DET	IND-SG	Definite=Ind|PronType=Art	3	det	_	_
3	field	field	NOUN	SG-NOM	Number=Sing	1	obj	_	_
4	is	be	AUX	PRES	Mood=Ind|Number=Sing|Person=3|Tense=Pres|VerbForm=Fin	6	cop	_	_
5	particularly	particularly	ADV	_	_	6	advmod	_	_
6	helpful	helpful	ADJ	POS	Degree=Pos	0	root	_	_
7	when	when	SCONJ	_	Case=Nom	9	mark	_	_
8	you	you	PRON	PERS-P2	_	9	nsubj	_	_
9	have	have	VERB	PRES	Mood=Ind|Tense=Pres|VerbForm=Fin	6	advcl	_	_
10	a	a	DET	IND-SG	Definite=Ind|PronType=Art	12	det	_	_
11	large	large	ADJ	POS	Degree=Pos	12	amod	_	_
12	amount	amount	NOUN	SG-NOM	Number=Sing	9	obj	_	_
13	of	of	ADP	_	_	15	case	_	_
14	source	source	NOUN	SG-NOM	Number=Sing	15	compound	_	_
15	data	data	NOUN	PL-NOM	Number=Sing	12	nmod	_	_
16	but	but	CCONJ	_	_	18	cc	_	_
17	you	you	PRON	PERS-P2	_	18	nsubj	_	_
18	want	want	VERB	PRES	Mood=Ind|Tense=Pres|VerbForm=Fin	9	conj	_	_
19	to	to	PART	_	_	20	mark	_	_
20	focus	focus	VERB	INF	VerbForm=Inf	18	xcomp	_	_
21	on	on	ADP	_	_	23	case	_	_
22	specific	specific	ADJ	POS	Degree=Pos	23	amod	_	_
23	areas	area	NOUN	PL-NOM	Number=Plur	20	obl	_	SpaceAfter=No
24	.	.	PUNCT	Period	_	6	punct	_	_
