A sweep effect isn't something you can just "find"...you have to MAKE it yourself. But to get anywhere you'll have to do some playing about with LMMS. You might make some horrible noises but you won't do any real harm and you'll find out stuff.
That video shows making a filter sweep using Triple Oscillator (TO). It's in the Instrument list (top symbol on LH side of screen) so just drag it over to BBE. Open it's Piano roll (double click on any block in BBE) and put in a long note. Then set TO to produce noise. O.k. so far ?
Now you can skip the video up to about 3:08 because it's just improving the sound and it would be better to get the basics sorted first (you can go back later to play with the Effects chain).So click on the Env/LFO tab, switch the filter on, select 2xLow pass and have a play with the "Freq" knob as BBE is playing. You should hear something like the sweep effect you're after. Still O.k. ?
Now you need to set up the Automation which basically makes LMMS do the knob twiddling for you. I think the video is pretty clear there but let us know how far you get and someone can walk you through anything that's still confusing.
Have fun - Steve
