Extraction of multiple 7 characters text substrings starting with "O-" from string of text

That works - thanks a lot! So I have two valid solutions for my question - Power BI community is awesome!

For those who will be looking at this post later for their purposes - in answer above replace [Column1] with [Description] and "OI-" with "O-".

I should've done that (see my reply to Eyelyn9) but it's customer's data - needs too much obfuscation. I made it work with List functions (also in my reply to Eyelyn9). Will try watkinnc' approach shortly just to have alternative.

Hi Nate,

Order numbers are embedded into string of text (300-400 characters) without commas. Not sure how many of them can be included (data is new to me, I came across 5 orders so far - and these are actually only 2 unique orders twice + error 🙂 ), so it makes it difficult to built robust solution. I managed to make it work with nested List functions (see response to Eyelyn9), thus avoiding to replicate logic on multiple split columns.
List functions rock :). 

I got away with List functions 🙂 - see reply above.

JS is something completely new for me as business user (but a lot of good stuff there, have to givve it a try at some point). Always nice to have alternative paths to solution. Thanks.

Vladisam  just so you know, for more complex scenarios, regex might be the only choice left and I am so glad that regex can be natively run IN PQ. 

Here is how that can be applied in your case.

Let's suppose your dataset is following

| Column1                                             |
|-----------------------------------------------------|
| LorempsumdolorsitametO123456eturadipiscingelitseddo |
| LorempsumdolorsitametO123456eturadipiscingelitseddo |
| LorempsumdolorsitametO12345turadipiscingelitseddo   |
| LorempsumdolorsitametOabcd12piscingelitseddo        |
| LorempsumdolorsitametOabcdpiscingelitseddo          |

You want to extract exact 7 consecutive characters in length dynamically anywhere from the string starting with O

let
    Source = Table.FromRows(Json.Document(Binary.Decompress(Binary.FromText("i45W8skvSs0tKC7NTcnPyS8qzixJzE0t8Tc0MjYxNUstKS1KTMksyCxOzsxLT83JLClOTUnJV4rVwaIvCQrI0A/XQbx9ChAAdW5iUnKKoRFx7oRrwFQeCwA=", BinaryEncoding.Base64), Compression.Deflate)), let _t = ((type nullable text) meta [Serialized.Text = true]) in type table [Column1 = _t]),
    #"Changed Type" = Table.TransformColumnTypes(Source,{{"Column1", type text}}),
    fx = let   fx =(input)=>
    Web.Page(
        "<script>
            var x='"&input&"';
            var b = x.match(/O[0-9A-Za-z]{6}/gm);
            document.write(b);
        </script>"){0}[Data]{0}[Children]{1}[Children]    
in
    fx,
#"Added Custom" = Table.AddColumn(#"Changed Type", "Custom", each fx([Column1])),
    #"Expanded Custom" = Table.ExpandTableColumn(#"Added Custom", "Custom", {"Text"}, {"Text"})
    
in
    #"Expanded Custom"

Sorry I think I should've shared the sample. My challenge was to extract only unique values from the list, which is a column in the table (or get only unique values into the list in the first place). I got this to work:
Table.AddColumn(#"Added Custom", "Try1", each List.Distinct(List.FindText(Text.Split([Description]," "),"O-")))

Thanks for reply, though.

Very elegant solution, however picks up only the first order - how do I pick up multiple ones and remove dupes?